Card counting is probably the best way to make money with the game. On the other hand, the practice involves some degree of risk, particularly to the extent that casinos intervene to expel you from the property. There's no guarantee that you'll end up winning a lot of money before a casino catches up with what you're doing. For each matched bet, you will be left with up to 95% of the free bet amount as a profit.
This is because betting exchanges usually charge a 5% commission on winnings. You may also suffer a very small loss in the qualifying bet due to the small difference in the odds on each website. This is normal and you'll get it back when you use the free bet. They have really active communities, dozens of automated and tracking tools, multiple sports, and most importantly, daily deals for existing customers to maintain the potential of continuing to earn money beyond new customer offers.
Stop gambling your money, find an advantage, try your paper-based system, and when you feel ready, don't risk more than 1% of your funds. Bookmakers make money thanks to big guys, casinos are guaranteed to make a profit due to the house edge, and poker rooms receive rake from every pot. An unmatched (or partially matched) bet at Betfair basically means that you have “offered” the payout bet, but there is not enough money backed up to cover you in full with the odds you choose. Some people who read about how to make money gambling are looking for a way to make consistent money in the long run.
My personal estimation is that 90% of potential card counters aren't good enough at what they do to make significant money. This means that your funds must be large enough for the stakes to be big enough to make as much money with the advantage you create. In addition, this allows me to see how much money I have left to go to the All-Stars in the end. But the lines and odds of the books are sometimes wrong, and if you can spot those situations, you can make money in sports betting.
They're exchanging money for entertainment, and as long as that doesn't get out of hand, that shouldn't be a problem for anyone. Players can lose money by design, as these games are created with a house edge that bites your potential winnings. If you do not match the total amount, you will not cancel the risk of the bet with the bookmaker and you could lose money. Any reputable guru who wants to tell you how to make money by betting will always tell you that there are no guarantees in life, and that doubles for gambling.
But I have made enough money with bookmakers in just six months to pay for a £860 (round trip) flight to Australia with matched betting.